[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 131043
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT WED JUL 13 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM
THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON
SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND
METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...SPECIAL FEATURE...

TROPICAL STORM EMILY IS CENTERED NEAR 11.1N 56.3W AT 13/0900 UTC
MOVING W AT 17 KT. ESTIMATED MINIMUM CENTRAL PRESSURE WAS 997
MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT.
SEE LATEST FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/
WTNT25 KNHC FOR MORE DETAILS. EMILY REMAINS TO THE SOUTH OF THE
STRONG SUBTROPICAL RIDGE AND WITH THE OUTFLOW NOT AS SYMMETRICAL
AS EARLIER. CONDITIONS REMAIN FAVORABLE HOWEVER FOR FURTHER
DEVELOPMENT AS IT MOVES W TOWARD THE WINDWARD ISLANDS. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 125 NM OF LINE
FROM 8N54W ALONG 11N58W TO 16N58W.

...TROPICAL WAVES...

EASTERN MOST TROPICAL WAVE IS ALONG 33W S OF 17N WITH A 1012
MB LOW ALONG THE WAVE NEAR 15N. THE SYSTEM IS MOVING W 10-15 KT.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60/75 NM
OF LINE 13N33W-10N37W AND WITHIN A 45 NM RADIUS OF 15.5N34W.

CENTRAL ATLC TROPICAL WAVE IS ALONG 40W S OF 16N MOVING W 10-15
KT. THIS IS A WEAK WAVE WITH LITTLE SIGNATURE CURVATURE OBSERVED
AND NO ASSOCIATED DEEP CONVECTION.

W CARIBBEAN TROPICAL WAVE IS ALONG 84W/85W S OF 18N MOVING W
10-15 KT. WAVE IS MOSTLY OVER CENTRAL AMERICA AND BENEATH STRONG
EASTERLY FLOW AT THE BASE OF A LARGE MID/UPPER HIGH THAT IS
CENTERED OVER THE N GULF OF MEXICO.

...THE ITCZ...

ITCZ AXIS IS CENTERED ALONG 11N13W 15N30W 10N35W 7N42W 13N53W
WHERE IT IS DISRUPTED BY TROPICAL STORM EMILY. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS OFF THE COAST OF AFRICA
WITHIN 120 NM OF LINE FROM 10N15W-13N21W AND SCATTERED MODERATE
CONVECTION IS WITHIN 100 NM ALONG THE COAST OF AFRICA FROM
8N-10N. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN
150 NM N OF THE AXIS FROM 40W-44W. CLUSTERS OF S SCATTERED
MODERATE CONVECTION ARE WITHIN 300 NM S OF THE AXIS FROM
41W-50W.

...DISCUSSION...

THE GULF OF MEXICO...
LARGE MID/UPPER LEVEL HIGH COVERS THE ENTIRE GULF OF MEXICO
CENTERED NEAR 26N89W. THIS IS LEAVING THE N GULF CLEAR AND DRY
WITH THE S GULF UNDER MOIST CONDITIONS. CLUSTERS OF SCATTERED
MODERATE/STRONG CONVECTION IS OVER THE S MEXICO AND THE BAY OF
CAMPECHE S OF 22N W OF 93W. ISOLATED SHOWERS ARE THE SE GULF AND
S FLORIDA S OF 27N FROM 80W-85W. AT THE SURFACE...A RIDGE AXIS
FROM THE W ATLC EXTENDING ACROSS THE GULF ALONG 28N TO THE COAST
OF TEXAS. THIS UPPER HIGH WILL RETROGRADE W ACROSS THE GULF AND
BE OVER MEXICO BY THE WEEKEND. THIS WILL GRADUALLY WEAKEN THE
SUBTROPICAL RIDGE OVER THE ATLC.

THE CARIBBEAN SEA...
THE MID/UPPER LEVEL HIGH DOMINATING THE GULF EXTENDS INTO THE
NW CARIBBEAN N OF 16N W OF 74W. THIS IS PRODUCING STRONG UPPER
EASTERLY FLOW OVER THE AREA. VERY SMALL WEAK MID/UPPER HIGH HAS
DEVELOPED OVER THE S CARIBBEAN NEAR 14N79W...AIDING IN THE
GENERATION OF CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG TO
SCATTERED STRONG CONVECTION S OF 14N W OF 71W TO INLAND OVER
CENTRAL AND SOUTH AMERICA. STRONG SUBSIDENCE REMAINS OVER THE E
CARIBBEAN FROM 11N-17N E OF 68W TO OVER THE LESSER ANTILLES.
THIS IS LIMITING SHOWER ACTIVITY AT THE MOMENT. THIS WILL
CHANGE AS OUTER RAINBANDS FROM T.S. EMILY ARE MOVING TOWARD
WINDWARD ISLANDS OVER THE NEXT FEW HOURS. BARBADOS IS ALREADY
REPORTING THUNDERSTORMS. ABUNDANT TROPICAL MOISTURE REMAINS OVER
THE GREATER ANTILLES W OF PUERTO RICO. THIS COULD PRODUCE
AFTERNOON THUNDERSTORMS LATER TODAY.

THE ATLANTIC OCEAN...
MID/UPPER LEVEL HIGH IN THE NE GULF EXTENDS ACROSS FLORIDA WITH
ANTICYCLONIC FLOW W OF 74W. MID/UPPER LEVEL TROUGH AXIS IN THE
CENTRAL/WESTERN ATLC EXTENDS S FROM A WELL DEFINED DEEP LAYERED
LOW WELL N OF THE REGION ACROSS BERMUDA TO 25N68W. WEAK
DIFFLUENCE E OF THE UPPER TROUGH IS GENERATING SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS WITHIN 75 NM OF LINE FROM 30N61W
TO BEYOND 32N58W WITH SCATTERED SHOWERS WITHIN 120 NM OF LINE
24N67W-30N61W. WEAK MID/UPPER RIDGE AXIS REMAINS IN THE
SOUTH-CENTRAL ATLC FROM NEAR 19N62W NE TO 26N56W. A SECOND
MID/UPPER LEVEL TROUGH IS IN THE EASTERN/CENTRAL ATLC WITH THE
TROUGH AXIS EXTENDING FROM AN UPPER LOW NEAR 31N45W S TO 25N47W.
THIS UPPER LEVEL FEATURE IS OVER A BROAD AREA OF SURFACE HIGH
PRESSURE THAT COVERS THE ATLC N OF 22N E OF 70W...THUS ONLY
STRATOCUMULUS LOW CLOUDS ARE APPARENT. BROAD MID/UPPER LEVEL
RIDGE COVERS THE E ATLC WITH A RIDGE AXIS EXTENDING FROM OFF THE
AFRICAN COAST NEAR 29N9W SW ACROSS THE CANARY ISLANDS TO NEAR
21N32W. MODERATE SUBSIDENCE AND DRY UPPER AIR COVERS THE AREA N
OF THE RIDGE AXIS E OF 20W.

$$
WALLACE



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